The invention relates to distribution valves for successively directing return water received from the high pressure side of a swimming pool pump through multiple outlet ports and pipes to various groups of pop-up cleaning heads embedded in the pool floor and wall surfaces.
A number of multi-port distribution valves for sequentially distributing pressure from the high pressure port of a swimming pool pump to various groups of cleaning heads imbedded in the bottom and side walls of the pool are known. These include the distribution valve disclosed in commonly assigned U.S. Pat. No. 4,523,606 by Gould et al., issued Jun. 18, 1985, entitled "DISTRIBUTION VALVE" and U.S. Pat. No. 4,570,663 by Gould et al., issued Feb. 18, 1986, entitled "DISTRIBUTION VALVE WITH DUAL CAMS TO PREVENT UNCONTROLLED EXCURSIONS OF VALVE BALLS", both of which are incorporated herein by reference. Each of the distribution valves disclosed in the above referenced patents includes an impeller-driven gear reduction mechanism and a plurality of outlet valves controlled in response to the gear reduction mechanism. U.S. Pat. Nos. 4,523,606 and 4,570,663 disclose gear reduction mechanisms which include a stationary planetary gear disposed about a vertical axis of the distribution valve, a pair of symmetric gear assemblies each driven by a gear attached to the impeller, with each of the symmetric gear assemblies being supported on a rotary gear support base, and each also having an outer gear engaging the teeth of the planetary gear to cause the rotary gear assembly base to rotate in response to rotation of the impeller and thereby drive at least one foot-shaped cam which rotates through a 360.degree. angle and sequentially displaces spherical balls from a valve seat of an outlet port. In each of the above prior distribution valves the pool return water from the high pressure side of the pool pump is fed into a vertical inlet pipe connected to the top of a dome-shaped cover section of the distribution valve.
The above mentioned distribution valves have been widely used, and the gear and impeller mechanisms have proven highly reliable. However, this inlet configuration adds considerable height to the entire distribution valve when installed. The resulting total height makes it impractical to install the distribution valve in a shallow deck box close to the edge of the swimming pool, so that the distribution valve and associated plumbing are out of sight. However, it would be highly desirable to be able to install a multi-port distribution valve in such a deck box. One reason is that it is desirable to have the distribution valve as close as possible to the pool so that lengths of PVC pipe as short as possible can be provided to couple the multiple outlet ports of the distribution valve to the various groups of cleaning heads embedded in the pool, in order to reduce the pressure drop to the cleaning heads. Such pressure drop reduces the force of the jets emitted by the pop-up cleaning heads in the pool surfaces, reducing their cleaning efficiency. The above mentioned deck box would have an easily removable cover to allow access to the distribution valve to facilitate servicing it. However, the height of the prior distribution valves, including roughly eight or more inches of inlet pipe (including a prior art pause valve) extending vertically upward from the top of the cover, and the need to keep the level of the distribution valve housing above the level of pool water, make it impossible to install the prior distribution valve in such a shallow deck box. This is because if the distribution valve with its eight or more inches of vertical connecting pipe on top were installed in a deck box, the distribution valve housing would be below the normal pool water level. Then, if the cover of the distribution valve were to be loosened to allow access to its interior for repair or service, the deck box would immediately be flooded with pool water, flooding the general area around the deck box, draining the pool down to the level of the top of the distribution valve housing, and generally making the service impossible or extremely difficult. Therefore, partial preliminary draining of roughly 4 to 6 inches of the pool water level (which, to say the least would be very inconvenient) would be necessary to bring its water level below that of the distribution valve.
Since it is not practical to install the above mentioned distribution valves in deck boxes at the edge of the pool decking, it often is considered necessary to locate the distribution valves a substantial distance from the pool, because the pool owner ordinarily wants the distribution valve and associated plumbing completely out of sight. In that case, each outlet port has to be coupled by a long PVC pipe to a group of cleaning heads. This results in increased plumbing costs. It also results in increased hydraulic resistance, and thus in a need to use higher horsepower pool pumps and larger amounts of electrical energy to operate the pool cleaning systems than would be the case if the distribution valve could be located in a deck box adjacent to the edge of the pool decking.
The assignee has provided an internal speed control valve in series with the above mentioned vertical inlet tubes to control the amount and direction of inlet water as it engages the impeller. This allows the user to adjust the amount of time each port is selected, and hence to adjust the total cycle time for cleaning the entire pool by removing the cover of the distribution valve and adjusting the desired speed. Adjustment of the impeller speed may be desirable when exceptionally large amounts of debris are blown into the swimming pool.
An external pause control feature has been provided on some of the above mentioned multi-port distribution valves, wherein a lever mechanism with an external control handle causes a vertical rod to move downward through a sealed sleeve bushing into the path of the impeller blade and thereby stop it from rotating. This causes a pause or halting of the cleaning cycle, which may be desirable when people are to be in the pool, for example, to prevent the people from stubbing toes on operating pop-up cleaning heads. However, the above mentioned external pause mechanism has been difficult to set, often requiring the effort of two persons, for example, a first person by a distribution valve located a considerable distance from the pool needs to actuate the pause control at the correct time, and a second person by the pool to observe the cleaning heads to determine when the desired pop-up heads are retracted and to signal the first person when to actuate the pause control.
One prior low profile distribution valve has been marketed by Sta-Rite, Inc. However, this device has not solved any of the above problems, for a variety of reasons. The Sta-Rite distribution valve feeds water from the high pressure port of the pool pump through a side wall of the cylindrical housing, directly into a structure forming a passage that leads to an inlet window of a cylindrical impeller chamber. The passage structure and the impeller chamber are attached to the lower surface of a cover clamped to the cylindrical housing, which contains an impeller and gear assembly that sequentially opens outlet ports of the housing. The cylindrical impeller chamber has a bottom which is solid, except for four radial slots extending outward from a central hole. When the cover is lowered onto the cylindrical housing, a four vane impeller is aligned with the radial slots and passes through them into the interior of the impeller chamber. Water pumped into the passage and flowing into the impeller chamber rotates the 4-vane impeller. Part of the water flows directly out through the 4 slots that admit the impeller vanes, and the rest is exhausted through an outlet window located in the cylindrical wall of the impeller chamber approximately 230.degree. measured around the wall of the impeller chamber from the inlet window in the direction of impeller rotation. The Sta-Rite distribution valve was notoriously inefficient and unreliable. In fact, the assignee once installed 1500 of the Sta-Rite distribution valves (under agreement with Sta-Rite's predecessor), and within a period of one year had to replace all 1500 of them with a prior distribution valve. Although the Sta-Rite valve is still on sale, it ordinarily has to be installed in conjunction with an inlet pressure bypass valve that limits internal pressure to about 18 pounds per square inch. This sharply reduces the impeller speed, and reduces the amount of water ejected by the cleaning heads served by the distribution valve. Furthermore, such a large portion of the water pumped into the impeller chamber of the Sta-Rite distribution valve escapes through the four slots which admit vanes of the impeller that impeller speed is considerably reduced from what it otherwise would be; the duration of each outlet valve cycle is correspondingly increased.
Bottom feed distribution valve mechanisms also are known, but they have had the problem of requiring too many 90.degree. elbows in the water lines and producing high hydraulic resistance. These devices are exceptionally difficult to service if removal is necessary.
Accordingly, there is an unmet need for an improved multi-port distribution valve which, while retaining the durability and reliability of the above mentioned multi-port distribution valves, can be conveniently installed in a shallow deck box adjacent to the pool decking around a conventional swimming pool, and which results in lower hydraulic resistance in the path from the outlet port of the swimming pool pump to the ejection nozzle of an actuated pop-up head. There also is an unmet need for such a device which can be easily serviced without flooding when installed in a shallow, out-of-sight deck box adjacent to a swimming pool, in which the distribution valve is installed. There also is an unmet need for an easily used impeller speed control system in a distribution valve.